JPS60165171A - Sub-scanner - Google Patents

Abstract

PURPOSE:To prevent uneven feeding from being generated on a recording picture by adding a count comparator and a driving force control circuit to a high speed facsimile equipment so as to control the amplitude of a drive power applied to a step motor corresponding to the length of a stop time at sub-scanning drive. CONSTITUTION:The counter comparator 2 is provided with a counter and a comparator. The counter is started when a motor clock 12 is lost and counts the synchronizing clock until the motor clock 12 to the next scanning line is generated. A reference value is set in advance to the comparator and when the result of count of the counter is compared with a reference value and the result of count is larger than the reference value, a ''high'' drive power control signal 13 is generated and when equal to or smaller than, a ''low'' signal 13 is generated. When the drive power control signal 13 applied is the ''high'' signal, a drive force control circuit 3 applies waveform correction changing the pulse width by retarding the trailing timing of a prescribed number of clock pulses in preceding over the motor clock 12 applied from a motor clock generating circuit 1 by a prescribed time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a sub-scanning device, and is particularly applicable to high-speed facsimile.
The present invention relates to a sub-scanning device that performs sub-scanning drive according to an image signal processing speed.

[Takumi rice technology]

For general 4C, high-speed facsimile 2, image information is encoded using the one-dimensional encoding method (M
H method) or two-dimensional encoding method (MR method) for transmission.

In encoding, the processing speed changes depending on the density of image information, so the transmission speed changes. Therefore, on the receiving side, 1
The image data corresponding to the scanning line is stored in the buffer memory.
Each time, recording is performed in units of scanning lines, and sub-scanning driving for one scanning line is performed. Therefore, the drive timing of sub-scanning for each scanning line varies depending on the density of the image information.
It doesn't become constant.

As shown in the graph of tactile characteristics in Figure 1, the step motor for sub-scanning drive is in a state where the inertia of the sub-scanning drive system including the step Tanabata remains immediately after the drive power has disappeared. In case B, the next driving power is supplied after the step motor has completely stopped, and in case B, the driving distance at startup is determined by the inertia. When the force is added to the starting force, the former becomes longer. The recording time for one scanning line is constant, and the moving length of the recording paper driven in sub-scanning during that time is longer in the former than in the latter.

The second sub-scanning device used in conventional high-speed facsimiles is:

Although the driving power supplied to the step motor is kept constant during busy periods, there is a drawback that the moving length of the recording paper is eclipsed and the recorded image is extended in the sub-scanning direction depending on the length of the stop time during the sub-scanning drive.

[Purpose of the invention]

An object of the present invention is to control the amount of drive power supplied to the step motor according to the length of the stop time during sub-scanning drive, to keep the moving length of the recording paper for each scanning line fairly constant, and to perform recording. An object of the present invention is to provide a sub-scanning device that can prevent an image from extending in the sub-scanning direction and causing unevenness in recording.

[Structure of the invention]

The sub-scanning device of the present invention includes a motor clock generating circuit that generates a motor clock corresponding to one scanning line in response to a sub-scanning instruction signal, and a sub-scanning driving circuit that counts the stop period of the motor clock and uses the sub-scanning drive circuit according to the counting result. a counting comparison circuit that outputs a drive power control signal for controlling the drive power of the step motor, and a waveform correction of the motor clock according to the drive power control signal to control the magnitude of the drive power of the step motor. The driving force control circuit is configured to include a driving force control circuit.

[Description of Embodiments] - Below, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the present invention, and the sub-scanning device includes a motor clock generation circuit 1, a count comparison circuit 2, a driving force control circuit 3, and a step motor 4.
- In FIG. 2, a motor clock generation circuit 1 generates a motor clock 12 consisting of a predetermined number of clock pulses of a predetermined cycle every time the sub-scanning instruction signal 11 is supplied.

However, the sub-scanning instruction signal 11 is a signal generated simultaneously with the recording instruction for one scanning line, and is supplied from a recording control section (not shown). Further, the number of clock pulses of the motor clock 12 is set to a reasonable number of steps of the step motor 4 in order to perform sub-scanning that is equal to one scanning line.

The motor clock generation circuit l is a counter circuit.

The number of synchronized clocks is set equal to the period of the motor clock corresponding to the rotational speed of the step motor 4 set in advance, and the counter is started every time the sub-scanning instruction signal 11 is supplied, and the synchronized clocks are activated. The motor clock 12 is generated by counting a predetermined number of pulses that are generated each time a set value is reached, and dividing the predetermined number of pulses by 172.

The counting comparison circuit 2 includes a counter and a comparator.

The counter starts when the motor clock 12 disappears and counts the synchronous clock until the motor clock 120 for the next scan line is generated.

A reference value is set in the comparator in advance, and the counting result of the counter is compared with the reference value. If the counting result is greater than the reference value, it is "high". If it is equal or smaller, it is "low". Drive power control A signal 13 is generated.

When the drive power control signal 13 to be supplied is "high", the drive force control circuit 3 controls the fall timing of a predetermined number of preceding clock pulses in the motor clock 12 supplied from the motor clock generation circuit 1. Is it possible to delay the process by a predetermined amount of time? 1-Perform waveform correction. Thereafter, a drive power 14 controlled by the waveform modified motor clock is output.

When the drive power control signal 13 is 10-'', the drive power 14 controlled by the motor clock 12 without waveform correction is output.O Drive power 14g is supplied to the step motor 4 and drives the step motor 4. The rotation of the step motor 4 is controlled by a paper feed 90-
The i'l-h recording paper is moved by a length corresponding to one scanning line.

In this way, by correcting the waveform of the motor clock 12 and increasing the driving power h4 to the step motor 4 when the sub-scanning stop time is long, the sub-scanning movement length of the recording paper during recording can be adjusted to a shorter stop time. It can be made equal to the sub-scanning movement length of the recording paper during recording when the length is short. Therefore.

By setting the moving length of the recording paper to be the width of one scanning line when the stop time is short, it is possible to prevent the paper from elongating.

As explained above, in the fujo example, the stop time is selected in two stages, long and short, but it goes without saying that the stop time can be selected in three or more stages depending on the length of the stop time.

〔Effect of the invention〕

As described above, the uninvented sub-scanning device adds a counting comparison circuit and a driving force control circuit, and increases the driving power supplied to the step motor in accordance with the length of the stop time during sub-scanning driving. 5. Control the temperature, especially the engineering. By keeping the sub-scanning moving length of the recording paper constant for every l scanning line, it is possible to prevent the printed image from extending in the sub-scanning direction, resulting in the effect that image quality can be improved.

[Brief explanation of the drawing]

Figure 1 shows the starting characteristics of a typical Step Tanabata:
77. FIG. 2 is a block diagram showing an embodiment of the invention. In the figure, l...Motor clock generation circuit,
2...Counting comparison circuit, 3...Driving force control circuit, 4...Step motor, 11...
...Sub-scanning instruction signal. 12... Motor clock, 13... Drive power control signal.

Claims (1)

[Claims] A motor clock generation circuit that generates a motor clock corresponding to one scanning line in response to a sub-scanning instruction signal, and a drive power for a step motor for sub-scanning drive that counts the stop period 1 of the motor clock and according to the result of counting. a counting comparison circuit that outputs a drive power control signal for controlling the step motor; and a drive force control circuit that corrects the shaping of the motor clock in accordance with the drive power control signal and controls the magnitude of the driving strength of the step motor. A sub-scanning device characterized by: